Method of corrugating sheet metal receptacles



June- 4, 1935. TAMTZ 2,003,981

METHOD OF CORRUGATING SHEET METAL REOEPTACLES Filed July 24, 1 2 Sheets-Sheet l nun l jnventou Jacyaas' JZarzz'lz 62 019? a 0361" June 4, 1935. J. STANITZ ET AL 2 Sheets-Sheet 2 grwentoaa, Jaeyzzes Jlanilz George 9. Boyer dummy fii l atenteci June 4, 1935 llNi'lED STATES METHOD OF CORRUGATING SHEET METAL RECEPTACLES Jacques Stanitz and George D. Boyer, Warren, Ohio, assignors to The Youngstown Pressed Steel Company, Warren, Ohio, a corporatio of Ohio Application July 24, 1933, Serial No 681,833

Claims.

Such receptacles may be used for many. purposes, for example, as tubs for power-driven washing machines; and it is desired that such corrugated receptacles have grooves, and the like, pref erably of uniform width, depth and contour throughout their extent, and/ or that the grooves, and the like extend upwards in the side walls of the receptacles from an intermediate portion of a curved corner wall provided between the integral bottom and side walls thereof.

It is therefore a principal object of the present invention to provide a method of making and corrugating sheet metal receptacles having the characteristics just described, in which grooves, channels, furrows, flutes, and the like, are provided in the receptacle side walls extending upwards therein from a preferably intermediate portion of the curved corner wall provided between the integral receptacle bottom and side walls.

Methods have been proposed and used for forming corrugated side walls for sheet metal'receptacles made from integral sheetblanks, but the same have either involved the formation of tapered corrugations in the side walls which extend completely to the top edge of the receptacles, or have involved the formation of usually quite shallow corrugations extending only in portions of the side walls and which do not extend upwards from an intermediate portion of a curved corner wall between integral receptacle side and bottom walls.

Another method of making sheet metal receptacles has been proposed in which a bottom wall is seamed or otherwise joined to separately made, formed and corrugated sheet metal side walls.

vHowever, all of these proposed methods produce receptacles which are not satisfactory for the purposes which are admirably'satisfied by our improved products, the method'of making of which, comprises one of the objects of the present invention.

It has, been proposed that substantially vertical corrugations may be formed in the side walls of a sheet metal receptacle drawn from a single sheet or blank of metal by circumferentially rolling the side walls between corrugating rolls having axially extending corrugations in their outer surface; or by stamping or pressing one or more corrugations successively around the periphery of the side walls of a receptacle.

However, such methods have proved unsuccessful because the corrugations provided thereby have full depth only for a portion of their extent, and the corrugations become shallow in other portions thereof. Moreover, the receptacle side walls are gathered or bulged inward so that a generally cylindrical outside receptacle contour cannot be maintained, because only one or relatively few corrugations are formed at any one time in the side walls by such methods and the side wall metal is thereby gathered, rather than being stretched bythe corrugating operation.

t has also been attempted to provide corrugations in the side walls of a deep drawn receptacle having an integral bottom wall by utilizing a punch cooperating with a female die having inwardly protruding die ribs provided with a contour in cross section corresponding to the contour of grooves desired to be provided in the receptacle side walls. However, the formation of ribs in the side walls of a receptacle by these means, even though the die ribs or bars are polished or formedfrom specially plated metal or from tool steel, produces scratches in the receptacle side walls where the corrugations are formed, so that the same are absolutely unsatisfactoryand cannot be provided with a vitreous enamel coating, which in many cases it is desired to provide on the receptacles which the present invention proposes to make.

It is therefore a further object of the present invention to provide'a method of making and corrugating the side walls of a deep drawn sheet metal receptacle which avoids all these difficulties and by which sheet metal receptacles having corrugated side walls may be satisfactorily made with resulting truly vertically extending side walls and which may be provided with a vitreous enamelled coating.

It is likewise a further object of the present invention to provide a method of making and corrugating the side walls of a deep drawn sheet metal receptacle by which either vertically or spirally extending grooves of either equal or varying length may be provided in the receptacle side walls.

' When sheet metal receptacles having integral side and bottom walls are utilized as tubs'for washing machines, it is desirable in many cases to provide special formations in the tub bottom wall for drainage purposes, and/or. to ofiset portions of the bottom wall from the remainder thereof, which bottom wall formations may be readily made during the receptacle drawing operation prior to corrugating the side walls.

It is therefore a further object of the present invention to provide a method of making and corrugating the side walls of a deep drawn sheet metal receptacle which when carrying out the corrugating operation will not distort bottom wall formations which may have been provided in the receptacle bottom wall when the receptacle blank is drawn.

And finally, it is an object of the present invention to provide a method of making and corrugating the side walls of a deep drawn sheet metal receptacle which satisfies the desiderata described above, which may be carried out in an inexpensive manner, and by which corrugated sheet metal receptacles having pleasing, attractive and distinctive appearances may be made.

These and other objects may be obtained by the steps, methods, processes and procedures hereinafter described in detail and claimed, preferred embodiments of apparatus for carrying out the same being shown in the accompanying drawings, which may be stated in general terms as including in a method of making a sheet metal receptacle having grooved side walls, a bottom wall and a curved corner wall therebetween, the steps of forming a receptacle blank from a single piece of sheet or plate metal preferably with a formed bottom wall and integral side walls and with a curved corner wall therebetween, and then forming spaced preferably relatively deep grooves in said side walls extending upwards from a portion of said curved corner wall by telescoping said formed receptacle blank upon a grooved male die having outer bounding surfaces conforming to the innersurfaces of said receptacle blank, by then clamping the formed bottom wall of said receptacle blank against said male die, and by then relatively telescoping said male die with the receptacle blank thereon, and clamped thereto in a female die having rolling die means corresponding in contour substantially to the contour of said male die grooves for forcing said receptacle blank into said female die to form grooves in said blank side walls progressively upwards from a portion of the curved corner wall thereof.

In the drawings,

Figure 1 is a view of a deep drawn receptacle blank having integral bottom and side walls with a curved corner wall therebetween;

Fig. 2 is a View of the receptacle blank after the same has been provided with grooves extending upwards in its side walls from an intermediate portion of the curved corner wall, according to the improved method;

Fig. 3 is an axial sectional view through die means on which the improved method may be carried out to form the corrugated receptacle shown in Fig. 2 from the deep drawn receptacle blank shown in Fig. 1;

Fig. 4 is an enlarged fragmentary sectional view of portions of the die means shown in Fig. 3;

Fig. 5 is a fragmentary sectional view taken on the line 55, Fig. 4;

Fig. 6 is a View similar to Fig. 1 of a deep drawn receptacle blank;

Fig. 7 is a view similar to Fig. 2 of a corrugated receptacle made from the blank shown in Fig. 6 having a modified form of side wall corrugations;

Fig. 8 is a view similar to Fig. 3, of the die means shown in Fig. 3 slightly modified to form the receptacle corrugations shown in Fig. '7

Fig. 9 is an enlarged fragmentary sectional view similar to Fig. 4 of the die means shown in Fig. 8; and

Fig. 10 is a fragmentary sectional view similar to Fig. 5, taken on the line |E l0, Fig. 9;

Similar numerals refer to similar parts throughout the various figures of the drawings.

The improved method may be carried out by forming the receptacle blank indicated generally .at H in Fig. 1 from a single piece of sheet or plate metal to provide a bottom wall 12, side walls I 3 integral therewith and with a curved corner wall l4 therebetween. The blank I I may then be provided with spaced grooves, channels, flutes, furrows and the like, indicated at I5 in Fig. 2 in the side walls 13 thereof extending upwards in the side walls preferably from an intermediate portion 35 of the curved corner wall M to form the corrugated receptacle generally indicated at IS in Fig. 2.

The method of making a corrugated receptacle l6 may be carried out on apparatus indicated more or less diagrammatically in Figs. 3, 4 and 5, which may comprise a male die ll, mounted in any usual manner on the press ram head l8, and a female die generally indicated at l9, mounted on the press base 20, the male and female dies I7 and I9 being relatively axially movable.

As shown in the drawings, the female die l9 may be provided with a series of removable rings 2| provided with a series of spaced axially extending grooves 22, a ring plate 23 being interposed between each ring for a purpose which will be hereinafter described.

The upper portion of the female die l9 may also be provided with a recessed ring plate 24, and a ring 25 provided with a series of grooves 28 for a purpose which will also be hereinafter described. Clamping air cushioning means may also be provided, including a clamping head 21, which may cooperate with the lower end of the male die ll, to clamp the receptacle blank [3 thereto; the clamping head 21 being mounted on piston rods 28 extending from an air cylinder 29, and the like.

A series of spherical balls 30 are located in each of the grooves 22 of each removable ring 2i; and a series of grooves 3| is provided in the outer. cylindrical surface 32 of the male die ll corresponding in number and location to the grooves 22 with balls 30 therein of the female die 19.

The male die I! may also be provided with a removable bottom plate 33 and the clamping head 21 may be provided with a removable top plate as for a purpose which will be hereinaf. described.

In carrying out the improved method, a single piece of sheet or plate metal is drawn to form the receptacle blank H with integral side walls l3 and bottom wall 52, and with a curved corner wall 84 therebetween. The side walls I3 of the receptacle blank H are preferably formed to be cylindrical, while the bottom wall 12 thereof may have any desired formation, for providing for drainage and the like, as by offsetting a portion of the bottom wall from the remainder thereof.

The receptacle blank II is then telescoped upon the grooved male die ll, which has outer bounding surfaces conforming to the inner surfaces of the receptacle blank, the removable bottom plate 33 thereof having a shape corresponding to the shape or inner contour of the bottom wall of the receptacle blank H.

The clamping air cushioning means is then operated to move the clamping head 21 against the bottom wall of the receptacle blank, so as to clamp the receptacle blank against the male die ll; the removable clamping head top plate 34 having a contourcorresponding 'tothe outer contour or shape of the formed receptacle bottom wall.

The purpose of clamping the bottom wall of the receptacle blank to the male die I1 is to hold the bottom wall shape in the manner in which it was formed during the drawing operation, so that it will not be pulled out of shape when the side walls I3 are being corrugated.

The removable parts 33 and 34 are provided so that different ones may be readily connected to the die I! and clamping head 21 to accommodate receptacle blanks having different bottom wall formations.

The male and female dies l1 and 19 are then relatively axially telescoped as by moving the press ram head i8 downward so that the receptacle blank II on the male die I! is forced into the female die IS in the manner bestillustrated in Fig. 4 of the drawings, whereby'the rolling die means or balls 30, which correspond in contour substantially to the contour of the grooves 31 in the male die I 1, form grooves in the blank side walls progressively upwards from a portion 35 of a curved corner wall [4 of the receptacle blank II.

The male die I! is then withdrawn from the female die l9 and the resulting corrugated receptacle [6 may then be stripped from the male die.

The corrugated receptacle product l6 illustrated and described, but not claimed herein, is illustrated, described and claimed in our copending application entitled Tub for washing machine, Serial No. 646,208, filed December 7, 1932, and also in our application entitled Sheet metal receptacles, filed of even date herewith,.which is a continuation in part of the common subject matter of said application Serial No. 646,208.

Moreover, the apparatus disclosed and described but not claimed herein, includes modified forms of apparatus such as are shown, described and claimed in our copending application, Serial No. 606,971, filed April 22, 1932, entitled Corrue gating apparatus.

The plates 23 are interposed between the rings 2| so as to relieve excessive pressure upon the lower balls of each series of balls 30 'in each groove 22 of each ring 21. Moreover, certain of the upper balls 30 in the grooves of certain of the upper rings 2| may be removed in stepped relation around the periphery of the female die I9 if it is desired to form corrugations of varying lengths in the side walls'of the receptacle extending from a portion of the curved corner wall thereof; such products being illustrated in said application entitled Sheet metal receptacles, filed of even date herewith.

Moreover, if it is desired to form spiral grooves in the receptacle side walls instead of vertically extending ones as illustrated, the same may be accomplished by relativelyrotating the male and female dies at the same time that the male and female dies are being relatively telescoped; such dies being shown in said application Serial No. 608,971.

The balls 30 being rolling die means, cause the grooves or corrugations l5 to have a uniform depth, width and contour in cross section throughout their length; it being clear that if it desired to make-(the grooves l5 deeper adjacent the bottom portion ofthe receptacle, than at the upper ends of the grooves, the same may be accomplished "by providing larger balls 30 in the lower rings 23 of the female die, a corre'sponding provisio'n being made in the grooves 3| of the In this manner, spaced relatively deep grooves may be formedin accordance with the improved method which'extend upwards from a portion of the curved, corner wall of a receptacle having integral, bottom and side walls, as best shown in Fig. 4;-and since the grooves are rolled in the side, walls, no scratches are ,made in the receptacle sidewalls during the corrugating operation, which would prevent. an unsatisfactory enamel coating from being applied 'to the receptacle. Z 1

Figs. .6 and 7 illustrate steps in the improved method for making another form of receptacle side Wall grooves, the receptacle blank H shown in Fig; 6,-being .formed from a single piece of sheet or plate metalwith a bottom wall l2, side walls l3 integral therewith and a curved corner wall I 4 therebetween. The blank ll may then be provided with spaced grooves generally indicated at l5a each comprising preferably substantially fiattenedportions l5b and a curved portion I50, the grooves l5a extending upwards in the side walls preferably from an intermediate portion 35a of. the curved corner wall I4 to form the corrugated receptacle generally indicated at l6a inv Fig. '7.

i The improved method described herein may be carried out, for making the receptacle I60. by slightly modifying the apparatus shown in Figs. 3, 4 and 5 to be as shown in Figs. 8, 9 and 10, as by utilizing a male die Ha having grooves 3Ia therein corresponding with the shape of the grooves l5a to be provided in the receptacle lBa. Likewise, the female die I9 is modified by removingthe balls 30 and placing rollers 30a having substantially cylindricalportions 30b, spherical ends 390 and an intermediate enlarged portion 30d; in the grooves 26 of the ring mounted above the ball rings 21.

The ring plate 24 is recessed at24a= to accommodate the enlarged portion d of each roller 30a; and the top member 36 of the female die I9 is also recessed at 3ladjacent each groove 26 to accommodate the enlarged portion 30d of each roll 30a. Theapparatus shown in Figs. 8, 9 and 10 is operated according to the improved method to force the receptacle blank I] into the female die I9 so that the rolls 30a form corrugations I5a in the side walls I3 thereof extending upwards.

by utilizing rolling die means having the desired shape.

Nor is it intended to limit the scope of the present invention to a method of making receptacles used solely as tubs for washing machines, be-

flutes and the like, which forin ribs, corrugations and the like in the side walls of sheet metal receptacles; and the word curved utilized herein as describing the receptacle corner wall is intended to refer to any type of shaped or rounded corner as distinguished from one which is sharp.

And finally, the term sheet metal used herein and in the appended'claims is intended to refer to sheet or plate metal according to the desired thickness of the material utilized.

The improved method therefore provides an inexpensive way of making attractive and distinctively appearing metal receptacles having integral bottom and side walls from a single piece of sheet metal having a series of grooves forming ribs extending upwards in the side walls of the receptacles, preferably from an intermediate portion of a curved corner wall provided between the bottom and side walls, without there being any resulting annular recess present in the receptacles below the lower ends of the ribs or corrugations, and without so injuring the receptacles that they may not be satisfactorily coated with a uniform vitreous enamel coating.

l. The method of making a sheet metal receptacle having grooved side walls, a bottom wall and a curved corner wall therebetween, which includes forming a receptacle blank with integral side and bottom walls and with a curved corner wall therebetween, and then forming spaced grooves in said side walls extending upwards from a portion of said curved corner wall by telescoping said formed receptacle blank upon a grooved male die having outer bounding surfaces conforming to the inner surfaces of said receptacle blank, and by then relatively telescoping said male die with said receptacle blank thereon in a female die having rolling die means corresponding in contour substantially to the contour of said male die grooves for forcing said receptacle blank into said female die to form grooves in said blank side walls progressively upwards from a portion of the curved corner wall-thereof.

2. The method of making a sheet metal receptacle having cylindrical grooved sidewalls, a bottom wall and a curved corner wall therebetween, which includes forming a receptacle blank from a single sheet of metal with cylindrical side walls, a bottom wall, and a curved corner wall therebetween, and then forming spaced grooves of uni form depth in cross section insaid side walls extending upwards from a portion of said curved corner wall by telescoping said formed receptacle blank upon a grooved male die having outer bounding surfaces conforming to'the inner surfaces of saidcylindrical receptacle blank, and by then relatively telescoping said male die with said receptacle blank thereon in a female die having rolling die means corresponding in contour substantially to the contour of said male die grooves for forcing said receptacle blank into said female die to form grooves in said blank side walls progressively upwards from a portion of the curved corner wall thereof.

3. The method of making a sheet metal recaptacle having grooved side walls, a formed bottom wall and a curved corner wall therebetween, which includes forming a receptacle blank with side walls, a bottom wall formed with an offset portion, and a curved corner wall therebetween, telescoping said formed receptacle blank upon a grooved male die having outer bounding surfaces conforming to the inner surfaces of said recep tacle blank, clamping the. bottom wall of said receptacle blank formed with an offset portion against said male die, and then forming spaced grooves in said receptacle blank side walls by relatively telescoping said male die with said receptacle blank thereon and clamped thereto in a female die having rolling die means corresponding in contour substantially to the contour of said male die grooves for forcing said receptacle blank into said female die to form grooves in said blank side walls progressively upwards from a portion of the curved corner wall thereof.

4. The method of making a sheet metal receptacle having grooved side walls, a bottom wall and a curved corner wall therebetween, which includes forming a receptacle blank with integral side and bottom walls and with a curved corner wall therebetween, and then forming spaced grooves of varying lengths in said side walls each extending upwards from a similar portion of said curved corner wall by telescoping said formed receptacle blank upon a grooved male die having outer bounding surfaces conforming with the inner surfaces of said receptacle blank, and by then relatively telescoping said male die with said receptacle blank thereon in a female die having stepped rolling die means corresponding in contour substantially to the contour of said male die grooves for forcing said receptacle blank into said female die to form grooves in said blank side walls of varying lengths progressively upwards from similar portions of the curved corner wall thereof.

5. The method of making a sheet metal receptacle having cylindrical grooved side walls, a bottom wall and a curved corner wall therebetween which includes forming a receptacle blank with integralrside and bottom walls and with a curved corner wall therebetween, and then rolling spaced grooves in said cylindrical side walls extending upwards from a portion of said curved corner wall by telescoping said formed receptacle blank upon an axially grooved male die having outer bounding surfaces conforming to the inner sur-' faces of said receptacle blank, and by then relatively telescoping said male die with said receptacle blank thereon in a female die having rotatable die means corresponding in contour substantially to the contour of said male die grooves for forcingsaid receptacle blank into said female die to roll grooves in said blank side walls progressively upwards from a portion of the curved corner wall thereof. g

JACQUES STANITZ. GEORGE D. BOYER. 

